High-power thermionic valve



Nov. 16 1926. 1,607,467

M. LATOUR men rowan THERMIONIC VALVE Filed bag. 5. 1923 2 Sheets-Sheet 1 avwcntoz Nov. 16 1926.

M. LATOUR HIGH POWER THERMIONIC VALVE Filed Dec..5, 1923 2 Sheets-Sheet 2 avwwxtoz F/ig. I0

I mus LATOUR MW Patented Nov. 16, 1926.

UNITED STATES PATENT orricle.

MARIUS LArouR, or PARIS, FRANCE, ASSIGNOR 'ro LA'i'oU CORPORATION. or 'JER- Y SEY CITY, NEW JERSEY, A coRroRA'rroNoF DELAWARE.

HIGH-POWER 'rHERMIoiv-Io vA vii.

Application filed December 5, 1923, Serial No. 678,575, and in France December fil, 1922.

The invention; relates to improvements in the so-called magnetron valves' of high power (see A. )V. Hull, Proceedings of the American Institute of Electrical Engineers,- to'r September, 1921, and atour, Radio lleview of London, November, 1'921). I

In the drawings, Fig. 1 depresents atherniionicdevice or valve for use in applicants systems. 1

Figs. 2, 3, 4 and 5 show various modified forms of the cathode structure for use" in said thermionic device' of valve,

Q Fig.6 shows a modified arrangement of theelectrodes of Fig. 1.

While Figs. 4 to 11 inclusive, diagram matically represent various circuit arrangements'or systems in Which'the mentioned valves or thermionic devices are employed.

According to Fig. 1 of th'e'drawing here with, these valves comprise a filament or cathode F with terminals 1 and 2, av plate or anode P with terminal 3, and an exterior coil B with terminals 4 'and' 5 designed to be passed by the current producing a magnetic control field in the spacecomprised betwee nhthe anode and the cathode.

.In, practice, in large power magnetrons,

the filament: has a rather great thickness, and it can be said that, as a consequence of coincidence between the axis of the filament and that of'the magnetic controlling field .heating of the filament.

producedby coil 13, the currents induced'inthis filament by the high frequency control field contribute, in a certain measure, to the Jow, according to the present ".this phenqmenonis developedand applied ode, to" such a point, indeed, that all outin a systematic manner by making the cathode of an appropriate shape in a manner so as to reduce appreciably theelectric force tonbe furnished by way-ofconduction from the'outsiderfor heating purposes of the oathsidesupply of current'can be. done away with:

With this'endin view, the cathode con-- stituted generally of tungsten 'or, tungsten coated with thorium, is made either in the shape of a hollow cylinder (see Fig. 2), or in the shape of'.a,series of spires or turns interconnected by generatrices (see Fig. 3),

min the shape of a closed helix (see. Fig. 4)", or else in'jthe shape of a series of generatrices of one and the same cylinder (see- Fig. 5), etc. In these different cases, the

field in" nagnctrons.

invention,

geometrical cylinder enveloping the cathode may have the same axis as coil B. But it alone, seeing that the induced current which contributexa certain magnetic action. But

one may arrange the cathode outside the anode as illustrated in Fig. 6,. where the cathode, by way of example, is given a shape as already shown .in Fig; 3. Under these conditions the magnetic field between anode and cathode may be appreciably smaller than the one normally generated by the coil B. In this way, it is feasible to a certain extent, by adopting a relative disposition of anode and cathode,.to cause the resultant value *offthe' high frequency. field (a1- lowing of auto-supply of the/ cathode) to coincide with that of the usual controlling But if these values cannot -be broiight coincide, it is possible to resort to the feeding of the coil by two currents of different frequencies ofwhich one creates the controlling field, and the other one the field".

for the self-feeding of the filament.

illustrated diagrammatically in Fig. 7.

cathode F is 'fed by-the source E through' oscillation circuit L-G. A reaction coil 1, through condenser feeds coil B. The

, flows through the cathode may be used to Such double-feeding scheme of coil-Biis Y The magnetrdncomprising plate P and sourceS which is to setup thefield Iiec'es 1 sary for the heatin of the filament "feeds wards coil Z the same as stopper A stops the current of coil Z towards source S; The frequency of source S will have to. be chosen so much higher the weaker the desired stray field ,shall be. "-In the operation of. the, arrangement'of Fig. 7 currentinduced in the filament F fromthe control .likewise coil B. A stopper A stops the flow of the current from,the 'source S towinding B heats the filament and causes plate current to-fiow in 'the plate circuit no including plate, P, plate battery E, oscil- .lation circuit LC, and the filament F, in-

duces a voltage inthe control circuit of the magnetron. This circuit includes control winding B of the magnetron, stopper A winding Z, condenser c to the other terminal of the winding B. The voltage induced in this circuit causes the controlling winding B to effect a larger plate current determined by the plate battery and the constants of the circuits.

By a combination of two magnetrons, it is possible to realize still more readily the separation of the two currents possessing different frequencies. Serviceable modes of connection are shown in Figs. 8, 9, and 10.

In Fig. 8 the two inagnetrons I' l? and P F work in parallel. Merely for the sake of indication, there have been added the direct current voltages c c which act in conformity with a well-known principle. Whereas reaction coil Z feedsthe coils B and B in series, source S feeds the same coils B and B in parallel, by using the middle point of coil L.

In Fig. 9 the relations are reversed. for the reaction coil Z feeds coils I3 and B in parallel by using the middle of the source S,

while source S feeds coils B and B in series.

In Fig. 10 there are shown the two magnetrons in such a way that, whereas the anode current diminishes in the one, it grows in the other, and vice versa. Coil L is then disposed in a different way, in fact, in a manner as indicated in the figure.

In Figs. 7,8, 9 and 10 auto-excitation of the magnetron has, been shown; but it could also be made to operate as an amplifier with or without addition of direct current voltage in coil B, as shown in Fig. 11.

From a view-point of construction, the cylindrical anode disposed inside or outside the cathode, ceuld constitute a wall part of the magnetron. The opening possibly necessary in the plate or in the metallic wall of the magnetron could be filled with an insulation material, or else could simply be made less conducting, with'the sealing being carried out in an up-to-date manner.

The starting of the magnetron could be eifected. in all of these cases, by the aid of an auxiliary source of high frequency current.

Having described myinvention, What I claim is:

1. A thermionic device comprising an anode, and a cathode and 'anelectromagcathode, and a winding surrounding said anode and cathode adapted to produce a magnetic field therebetween, said cathode being constructed and arranged to be heated solely by currents induced therein by said controlling winding.

3. In a thermionic device, the combination of an anode, a cathode and a" controlling winding located in proximityto said anode and cathode, means for supplying heating currents of predetermined frequency to said controlling winding, and means for supplying currents of different frequencies to said controlling winding.

1'. In a thermir. iic device, the combination of an anode, a cathode and a controlling winding adapted to produce a magnetic field between said anode and cathode, means f or supplying heating currents of a predetermined frequency to said controlling winding, means for supplyingcontrolling currents of different frequencies to said controlling winding, and means inserted in the circuit of said controlling winding for maintaining separation between heating currents and controlling currents in their respective sources.

In a system of the class described, a thermionic device including a cathode, an anode, and an electron'iagnetic control-element for controlling space current between said cathode and said anode, a source of potential for said anode, and means for heating said cathode by currents induced there inby said electron'iagnetic control'element.

6. In a system of the class. described, an electron discharge device having a cathodc and an anode, input and output circuits connected to said electron discharge device,

electromagnetic controlling means in said input circuit, means for heating said cathode 8. In a system of the class described, two' thermionic devices each having elements 1neluding a cathode, an anode and a controlling winding, circuits in whlch sa d elements are connected in opposition, and means including said controlling windings for heating said cathodes by currents induced therein.

MARIUS LAT'OUR' 

